The demo is full of little things which could be optimized. The undocumented group inventory (-> double click on the sinus curve in the inventory) should be activated. (Careful when you use it. I'm not sure if or when it resets.). Esc should lead to the main menu. Now there are 2 similar menus, one with save and one without. Why?

Of course there are still dozens of hidden bugs and balancing issues. Plan&Go sometimes swallows commands at very close range. The enemy can shoot through a wall in the hospital. Grenades take too long to explode. Pistols and Uzis are quite useless, I think. The sniper rifle is overpowered. Guns are unloaded if you use another one.
All no big deal, but it remains to be seen if they really allocate the resources to clean it up.

Ive i read all of that, i guess i will wait a bit longer to actually start the game.
Perhaps a patch or 2.